Method of joining the ends of high-tension electric cables and an improved junction box therefor



Oct. 13, 1931. c. F. PROOS 1,327,609 METHOD OF JOINING THE ENDS OF HIGH TENSION EmEC'l'fiIC CABLES AND AN IMPROVED JUNCTION BOX THEREFOR Filed Jan. 16, 1928 Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE CORNELIS I'REDERIK PROOS, OF DELFT, NETHERLANDS, ASSIGNOR TO NAAMLOOZE VENOOTSCHAP NEDERLANDSCHE KABELEABRIEK, OF DELFT, NETHERLANDS, A

DUTCH COMPANY ,METHOD OI' J'OINING TEE ENDS F HIGH-TENSION ELECTRIC CABLEKAND AN IMPROVED JUNCTION BOX THEREFOR Application filed January 1.6, 1928, Serial No. 247,245, and in the Netherlands March 29,1927.

For joining the ends of high-tension electric cables it has been the usual practice heretofore to use lead sleeves enclosed in an iron shell, the lead sleeve usually being soldered to the lead sheath of the cable.

Soldering the sleeve on to the sheath of the a cable is, however, attended with difficulties, owing to the high temperature required, and especially when it is a question of heating and soldering the sheaths of cables of large dimensions, in which case considerable masses have to be heated.

A method of joining the ends of high-tension electric cables is known, according to which the ends of the cable are inserted into a junctionbox, and atight pointismadebetween the lead sheathing of the cable and the wall of the junction box by means ofa stufling box with metallic packing material. ACCOIdIIIg to the present invention the filling materlal for the stufiing box consists of small leaves or strips of lead wool, lead waste or like particles of soft metal or a soft metallic alloy, in

which metal rings are disposed at predetermined intervals. Such packing has the advantage of yielding and therefore of being easily compressible, without, however, damagingthe lead sheathing of the cable.

The invention also relates to a unction box adapted for carrying out said method, wherein the stalling boxes are enclosed, with a predetermined amount of free space by a casing which may be provided with closable openings. The space between this casing and the stufiing box .may be filled with cast insulating material, thus effectually making a tight joint between the sheath of the cable andthewall 'on the junction box. v

One form of the'invention is illustratedby the accompanying drawing, which represents, in longitudinal section, a portion of a stufling box. 1 is theend of a cable between which and the wall of the junction boxa tight joint isto be made; 2 is the wall of the'junction box, the interior 3 of which is filled with liquidoil (not shown). The end of the juncis arranged packing material 4, which consists preferably of small leaves of lead' wool, lead waste or like particles of soft metal or of tion box is arranged as a stufling box in which a soft metallic alloy, an inner end plate or lining 5, and a gland 6. The gland 6 is pressed home by means of a cap 7, formed with an internal thread engaging a corresponding thread 8 on the end of the junction box. In order to obtain a close interconnection ofthe whole packing, metal rings 16 are interposed at predetermined intervals, which enable the packing material to be compressed firmly, and at the same time close any passages which may still remain between the metal leaves.

In this manner the oil filling is prevented from leaking out through the stufiing box.

' WVith the arrangement shown in the drawing, that portion of the stufling box which is located on the outer side of the ring15 (towards the left of the drawing) may, if desired, be filled with ordinary packing material. In the example shown in the drawing, the

stufiing box is enclosed in a second casing orcap 9, connected by bolts e. g. as at 10 with flanges 11 formed, for this purpose, on the junction box, a packing ring 12 being interposed. The casing 9 is formed with an integral bushing 13 which fits round the cable sheathing 1. The upper part of the casing 9 is formed with a number of openin s, closed by screws 14, which are adapted for lling the space between the stuffing box and easing with insulating material, whereby a perfect- 1y tight joint is established between the lead sheathing and the junction box, Whilst the insulating material protects the stufiing box from the influence of external moisture.

What I claim is:

1. In combination with ajunction box having a main casing,- a stuffingbox, an outer fcasing through which the cablepass'es, fixed to said main casing and enclosing said stuifing box, of a plurality'of soft metallic packin rings arranged in said stulfing box around said cable and a plurality of hard metallic rings spacedlyinterposed between saidsoft metallic packing rings.

2. A junction box for electric cables having a main casing adapted to be filled with an in; sulating liquid, said casing having a stufl'in'g j box therein, a plurality of packing rings ar- 1 ranged in sai (1 stufiing box around said cable,

means for compressing said packing ring and an outer casing fixed to said main casing adapted to be filled with insulating liquid 5 and enclosing said stufling box and having an integral bushing through which the electric cable is adapted to pass.

In testimon CORN Whereef I aflix my signature.

E LIS FREDERIK PROOS. 

